U.S. patent number 8,419,338 [Application Number 12/665,212] was granted by the patent office on 2013-04-16 for work conveying apparatus.
This patent grant is currently assigned to Toyota Jidosha Kabushiki Kaisha. The grantee listed for this patent is Hitoshi Konosu, Tadashi Odashima. Invention is credited to Hitoshi Konosu, Tadashi Odashima.
United States Patent |
8,419,338 |
Konosu , et al. |
April 16, 2013 |
**Please see images for:
( Certificate of Correction ) ** |
Work conveying apparatus
Abstract
Since both a driving means for lifting a work and a driving
means for turning operation must have been arranged in a
conventional work transfer apparatus, the apparatus has been large
in size and heavy in weight. A work transfer apparatus is provided
with a holding tool for holding a window, i.e., the work, and a
supporting arm for movably supporting the holding tool. The window
held by the holding tool is transferred by a supporting arm to
window frames to which the window is to be assembled, and the
posture of the window is changed to that corresponds to the window
frames. Furthermore, the supporting arm is configured to be a
closed loop link mechanism wherein a plurality of links are
connected to form a closed loop. The posture of the holding tool
one link of a pair of links connected to the holding tool of the
supporting arm can be fixed.
Inventors: |
Konosu; Hitoshi (Nagoya,
JP), Odashima; Tadashi (Owariasahi, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Konosu; Hitoshi
Odashima; Tadashi |
Nagoya
Owariasahi |
N/A
N/A |
JP
JP |
|
|
Assignee: |
Toyota Jidosha Kabushiki Kaisha
(Toyota-Shi, JP)
|
Family
ID: |
40304443 |
Appl.
No.: |
12/665,212 |
Filed: |
July 25, 2008 |
PCT
Filed: |
July 25, 2008 |
PCT No.: |
PCT/JP2008/063826 |
371(c)(1),(2),(4) Date: |
December 17, 2009 |
PCT
Pub. No.: |
WO2009/017214 |
PCT
Pub. Date: |
February 05, 2009 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20100183414 A1 |
Jul 22, 2010 |
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Foreign Application Priority Data
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|
|
|
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Jul 30, 2007 [JP] |
|
|
2007-197928 |
|
Current U.S.
Class: |
414/590; 212/292;
74/490.01; 901/15 |
Current CPC
Class: |
B25J
9/107 (20130101); B62D 65/06 (20130101); B25J
5/02 (20130101); B25J 15/0616 (20130101); B66C
1/0256 (20130101); B66C 1/0243 (20130101); B25J
15/0052 (20130101); Y10T 74/20305 (20150115) |
Current International
Class: |
B25J
17/00 (20060101) |
Field of
Search: |
;414/680,591,590,589
;901/16,15 ;74/490.01 ;212/328,292,71 ;269/559,22 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
1919545 |
|
Feb 2007 |
|
CN |
|
10 2005 055678 |
|
Apr 2007 |
|
DE |
|
0 658 403 |
|
Jun 1995 |
|
EP |
|
2 172 313 |
|
Apr 2010 |
|
EP |
|
63-284072 |
|
Nov 1988 |
|
JP |
|
04-189493 |
|
Jul 1992 |
|
JP |
|
07-137675 |
|
May 1995 |
|
JP |
|
08-080880 |
|
Mar 1996 |
|
JP |
|
10 146781 |
|
Jun 1998 |
|
JP |
|
11-245124 |
|
Sep 1999 |
|
JP |
|
2003-311663 |
|
Nov 2003 |
|
JP |
|
1 627 401 |
|
Feb 1991 |
|
SU |
|
Other References
Office Action issued Sep. 21, 2011 in Canadian Application No.
2,692,825. cited by applicant.
|
Primary Examiner: Underwood; Donald
Attorney, Agent or Firm: Kenyon & Kenyon LLP
Claims
The invention claimed is:
1. A work conveying apparatus, holding a work, conveying the work
to a work-assembly position, and changing a posture of the work in
accordance with the work-assembly position, the apparatus
comprising: a holder for holding the work; and a support arm for
supporting and conveying the holder to the work-assembly position,
wherein the support arm is constructed as a quadrate closed loop
link mechanism, the support arm comprising a first upper link, a
second upper link, a first lower link and a second lower link, ends
of the first upper link and the second upper link being connected
by an upper joint, ends of the first lower link and the second
lower link being connected by a lower joint, ends of the first
upper link and the first lower link being connected to a first
middle joint, and ends of the second upper link and the second
lower link being connected to a second middle joint, wherein the
lower joint connects the first lower link, the second lower link
and the holder rotatably, the lower joint comprising a connect
member connected between the lower links and the holder for
connecting selectively the holder to either one of the lower links
without relative rotation for fixing the posture of that link and
the holder.
2. The work conveying apparatus as set forth in claim 1, the
holder, comprising: an offset link connected to the lower joint;
and a drive member for fine turning an angle between the offset
link and either one of the lower links.
Description
This is a 371 national phase application of PCT/JP2008/063826 filed
25 Jul. 2008, claiming priority to Japanese Patent Application No.
2007-197928 filed 30 Jul. 2007, the contents of which are
incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a work conveying apparatus,
holding a work, conveying the work to a work-assembly position, and
changing the posture of the work corresponding to the work-assembly
position.
BACKGROUND OF THE INVENTION
Conventionally, in the assembly line of a vehicle, when a work is
assembled to the vehicle, which is difficult for an operator to
transfer, set, or assemble (called "a large work" involving a front
window or a rear window), a work conveying apparatus is used, which
assists to support the work, reduces the load to support the work
for the operator, and which assists to convey the work, reduces the
load to operate the work. Thus, work conveying apparatus is known
as a power assist apparatus.
As the work conveying apparatus, JP-A-11-245124 discloses the work
lifting apparatus including a holder and a supporter, the holder
holds the work, the supporter moves the holder vertically and
supports to the holder with inclination. This work lifting
apparatus detects the inclination of the holder operated by the
operator and lifts the holder by the supporter on the detected
direction and angle about the inclination of the work.
The lifting of the holder is achieved, for example, by a driver of
the supporter, which moves the supporter telescopically, and the
supporter lifts the holder.
Typically, the work conveying apparatus conveys the work to the
position where the work is assembled to the body, and then the work
is assembled to the body. For example, as the holder is inclined to
the supporter, the posture of the work can be turned in accordance
with the position.
The work lifting apparatus includes a driver involving a motor, the
driver rotates the holder to the supporter, and the work can be
inclined in accordance with that of the body.
Thus, the work lifting apparatus disclosed JP-A-11-245124 includes
two independent drivers for lifting and rotating the work.
In the work lifting apparatus, for example, when the window as the
work is assembled to the window frame of the vehicle as the body,
the holder holding the work is moved down by the driver for
lifting, and rotated by the driver for rotating, and inclined in
accordance with the inclination of the window frame.
In this case, the rotating of the window is needed to finish during
the desired time on tact time of the assembly line, when the heavy
article such as the front window or the rear window ("the large
work") is rotated by the desired angle during the desired time, the
rotating driver tends to be large and heavy.
Furthermore, the lifting driver needs to lift rotating driver as
well as the holder and the work. Thus, if the rotating driver is
large and heavy, the lifting driver is needed to have the large
capacity of lifting, so that the work lifting apparatus should
become large and heavy.
The purpose of the invention is to provide a new work conveying
apparatus, which is constructed to be small and light.
SUMMARY OF THE INVENTION
A work conveying apparatus of the first aspect of the present
invention, includes a holder holding the work and a support arm
supporting and conveying the holder to the work-assembly position,
in which the support arm is constructed as a quadrate closed loop
link mechanism connected by plural links, in which the holder is
connected by a pair of the links in the plural links, and in which
the posture of the holder against the one link in the pair of the
links is fixed.
Due to the above structure, the work conveying apparatus may only
include the driving means for lifting the work without the driving
means for rotating it, the driving means for rotating is dispensed,
so that the weight supported by the arm is lightened, the driving
means for lifting the work can be downsized and lightened and
altogether the work conveying apparatus can be downsized and
lightened.
In the work conveying apparatus of the present invention, the
support arm preferably includes a joint member connecting the pair
of the links and the holder rotatably; and a connect member
connecting selectively the holder to either the link without
relative rotation for fixing the posture of the link.
Due to the above structure, the holder can be easily and surely
fixed the posture against the one link in the pair of the
links.
In the work conveying apparatus of the present invention, the
holder preferably includes a drive member for fine tuning the
posture of the link.
Due to the above structure, the accuracy for tuning the posture of
the work and the quality for assembling the work to the body can be
improved.
As mentioned above, according to the present invention, the work
conveying apparatus dispenses the driving means for rotating is
dispensed, so that the weight supported by the arm is lightened,
the driving means for lifting the work can be downsized and
lightened and altogether the work conveying apparatus can be
downsized and lightened.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side view showing a work conveying apparatus with a
support arm shortening vertical length.
FIG. 2 is a side view showing the work conveying apparatus with the
support arm extending the vertical length in the state the rotation
angle of an offset link and a first lower link is fixed.
FIG. 3 is a side view showing the work conveying apparatus with the
support arm extending the vertical length in the state the rotation
angle of the offset link and a second lower link is fixed.
FIG. 4 is a ground section view showing the part of a lower joint
in the support arm in the state that a piston for fixing the
rotation angle is inserted in holes for switching the joint
position of the first lower link and the offset link.
FIG. 5 is a side view showing the part of the lower joint in the
support arm
FIG. 6 is a ground section view showing the part of the lower joint
in the support arm in the state that the piston is inserted in the
holes for switching the joint position of the second lower link and
the offset link.
FIG. 7 is a ground section view showing the part of the lower joint
in the support arm with a motor for fine tuning the angle of the
offset link to the first upper link and the second lower link.
FIG. 8 is a side view showing the work conveying apparatus in the
state that the vertical force works the holder by a wire of a
balancer structure, which supports the gravity of the holder and
the window and cancels the gravity working the support arm.
FIG. 9 is a side view showing the work conveying apparatus in the
state that the vertical force does not work the holder by the wire
of the balancer structure, which supports the gravity of the holder
and the window and cancels the gravity working the support arm.
DETAILED DESCRIPTION OF THE INVENTION
A work conveying apparatus 1 conveys, positions and assembles a
work to the given position three-dimensionally, with intended by a
worker, in concert with the worker or by itself. The work is
difficult for the operator to transfer, set, or assemble (called "a
large work" involving a front window or a rear window).
The work conveying apparatus 1 positions and assembles a window 5
as the work to a rear window frame 7a or a front window frame 7b of
a vehicle 7, which is transferred to the left along an assembly
line L shown in FIG. 1. The work conveying apparatus 1 includes a
holder 20, a supporting arm 10, an overhead trolley 40 and a
controller 80. The holder 20 holds the window 5. The arm 10
three-dimensionally supports the holder 20. The trolley 40 is
disposed above the arm 10, and supports and transfers the arm 10
along the parallel direction of the assembly line L. The controller
80 controls the arm 10 and so on.
The work conveying apparatus 1 positions and assembles the window 5
to the rear window frame 7a and the front window frame 7b of the
vehicle 7, but it may be applied to apparatuses which assembles the
other window involving a side window, the other parts involving a
bonnet or the like.
The trolley 40 includes a main body 41, wheels 42. The wheels 42
are set to the body 41, and engaged to a rail 9, which is laid down
in the transfer direction of the assembly line L. The wheels 42 are
engaged to the rail 9, so that the trolley 40 is supported by the
rail 9.
Thus, the trolley 40 is supported by the rail 9 and travels along
the rail 9 (along the transfer direction of the assembly line
L).
The arm 10 is constructed a quadrate closed loop link mechanism,
which is connected by a first upper link 11, a second upper link
12, a first lower link 13 and a second lower link 14. The ends of
the links 11 and 12 are connected by an upper joint 15, the joint
15 is supported by the body 41, the ends of the links 13 and 14 are
connected by a lower joint 18, the ends of the links 11 and 13 are
connected by a first middle joint 16, the ends of the links 12 and
14 are connected by a second middle joint 17.
The joint 15 is an active joint rotatably supporting the links 11
and 12 in the direction of the assembly line L, including motors,
in which the one rotates the link 11 around the joint 15, the other
rotates the link 12 around the joint 15.
An offset link 22 is connected to the joint 18 and is extended from
a body 21 of the holder 20, and can be rotated around the joint 18
in the direction of the assembly line L.
The link 22 can fix the rotation angle (the position) selectively
against the link 13 or 14, which are connected to the link 22.
The joint 16 is a passive joint rotatably supporting the links 11
and 13 in the direction of the assembly line L, and the joint 17 is
a passive joint rotatably supporting the link 12 and 14 in the
direction of the assembly line L.
The arm 10 is not especially limited to be configured as the closed
quadrate loop mechanism connected by the four links, may be
configured as a closed loop mechanism connected by the different
numbers of the link. It may include a pair of the links connected
to the link 22, such as the links 13 and 14 connected to the link
22 by the joint 18.
The holder 20 includes plural suction pads 30 (four pads) to hold
the window 5, the pad 30 is disposed at the body 21 of the holder
20.
The number of the pads 30 is not especially limited to be four,
which is the same number of the corners of the window 5. The holder
20 may include the three or more than four pads.
The controller 80 controls the motors disposed in the joint 15 for
driving the arm 10, the switch either holding or releasing the
window 5 by the pads 30 of the holder 20 and the like.
Due to the work conveying apparatus 1 configured as the above
structure, the window 5 is assembled to the rear window frame 7a as
following.
As shown in FIG. 1, keeping the holder 20 upper by the arm 10, when
the holder 20 holds the window 5, the ends of which is coated with
the adhesive, by the pads 30, the trolley 40 travels along the rail
9 and the window 5 is conveyed near the rear window frame 7a.
Actually, when the window 5 is conveyed to the vehicle 7, the arm
10 is rotated to shorten the vertical length (the links 11, 12 are
driven to rotate in the direction in which the inner angles of both
links become wide inside the closed link loop), so that the window
5 is kept upper.
The window 5 is held horizontally by the holder 20 in the
upper.
When the window 5 is conveyed along the rail 9, the following
structure for travelling the trolley may be adopted; for example,
the trolley 40 travels along the rail 9 cooperated with the
operation of the operator with handling the holder 20, and the
trolley 40 travels along the rail 9 itself.
When the window 5 is conveyed to the rear window frame 7a of the
vehicle 7, the arm 10 is rotated to extend the vertical length (the
links 11, 12 are driven to rotate in the direction in which the
inner angles of both
links become narrow inside the closed link loop), so that the
window 5 is moved down.
If the work conveying apparatus 1 assembles the window 5 to the
rear window frame 7a, the rotation angle .theta.1 of the link 22 to
the link 13 is fixed. The rotation angle .theta.2 of the link 22 to
the link 14 is not fixed, so that the link 22 can rotate against
the link 14.
When the arm 10 is driven to extend the vertical length and the
window 5 is moved down, as shown in FIG. 2, the posture of the
links 11, 12, 13 and 14 of the arm 10 is turned from the horizontal
posture to the vertical posture. The rotation angle .theta.1 to the
link 13 is fixed, so that the window 5 is rotated rightward around
the joint 18, which is held by the holder 20 connected to the
offset link 22, and the window inclines leftward, in other word,
the position of the left end of the window 5 is upper than that of
the right end (see FIG. 2).
In this case, the window 5 is moved down to the height of the
position of the rear window frame 7a, the rotation angle .theta.1
and the like are set, where the slope angle of the rear window
frame 7a is substantially same as that of the window 5.
Thus, after the window 5 is moved down to the position of the rear
window frame 7a, the window 5 is fitted to the rear window frame 7a
by the operator.
Further, the window 5 is pressed to the rear window frame 7a and
the adhesive 6, coated around the window 5, is pressed by the
window 5 and the rear window frame 7a, the window 5 is assembled to
the rear window frame 7a.
If the window 5 is assembled to the front window frame 7b, the arm
10 is driven to extend the vertical length, the window 5 is moved
down, in this case, the rotation angle .theta.1 of the link 22 to
the link 13 is not fixed, the rotation angle .theta.2 of the link
22 to the link 14 is fixed, so that the link 22 can be rotated
around the link 13.
Thus, as shown in FIG. 3, the window 5 is moved down by the
extending motion of the arm 10, is rotated leftward around the
joint 18, inclines rightward, in other word, the position of the
right end of the window 5 is upper than that of the right end.
In this case, the window 5 is moved down to the height of the
position of the front window frame 7b, the rotation angle .theta.2
and the like are set, where the slope angle of the front window
frame 7b is substantially same as the window 5.
Thus, the offset link 22 can be fixed in the rotation angle
.theta.1 to the link 13 or in the rotation angle .theta.2 to the
link 14, which are connected by the joint 18.
The structure capable of fixing the rotation angle .theta.1,
.theta.2 will be described.
As shown in FIGS. 4 and 5, the links 13, 14 and 22 are set, in the
rotate center of the joint 18, the link 22 is arranged between the
links 13 and 14. In the part of the links 13, 14 and 22 which are
connected by the joint 18 (in the lower ends of the links 13, 14
and the upper end of the link 22), there are sleeves 13a, 13a, 14a,
14a, 22a and 22a formed arc with the desired width.
The sleeves 13a, 14a and 22a are formed, which go through the links
13, 14 and 22, respectively, in the direction of the rotate center
axis of the joint 18.
The numbers of the sleeves 13a, 14a and 22a are not limited, in
this embodiment, the two sleeves (13a, 13a, 14a, 14a, 22a and 22a)
are formed.
Coupling shafts 18a are inserted to the sleeve 13a, 14a and 22a,
the shafts 18a connect the links 13, 14 and 22 at the joint 18.
The shaft 18a can slide along the arc form as the sleeves 13a, 14a
and 22a.
The links 13, 14 and 22 are connected rotatably around the center
of the joint 18.
Thus, the shafts 18a serve as the coupling member connecting the
links 13, 14 and 22 rotatably.
The both ends of the shaft 18a are fixed to stops 18b (at the side
of the link 13) and 18c (at the side of the link 14).
Thus, the ends of the shafts 18a are set to the stops 18b, 18c, so
that the shafts 18a can be prevented from pulling out the sleeves
13a, 14a and 22a and can fix the relative positions. The positions
of the shafts 18a are fixed such that the each shaft 18a slides in
the sleeves 13a, 14a and 22a as the same manner. The each position
of the shaft 18a is set to the same phase in the sleeves 13a, 14a
and 22a.
Holes 13b, 14b and 22b are formed to go through the links 13, 14
and 22 along the direction of the rotation axis, and formed inner
than the shafts 18a inserted to the links 13, 14 and 22.
The holes 13b, 14b and 22b are formed as circles in which a part of
the peripheral is cut straightly (hereinafter called "cut-circle")
in section (see FIG. 5).
The joint 18 includes a fixing plunger 19. The plunger 19 includes
a piston 19a, a pin 19b and a body 19c, the piston 19a is for
fixing the rotation angle and is column which has the cut-circle
sectional form to fit the holes 13b, 14b and 22b, the pin 19b
extends from the end of the piston 19a, and the body 19c supports
the pin 19b slidably along the axis direction.
The body 19c is fixed in the axis direction of the links 13, 14 and
22.
The piston 19a is constructed to change the position of the links
13, 14 and 22 in the axis direction by means of sliding the pin 19b
in the body 19c.
The length of the piston 19a is designed such that the following
condition (1) and (2) is satisfied. (1) The length is longer than
the gap between the links 13 and 22, shorter than the total length
of the gap and thickness of the links 13 and 14. (2) The length is
longer than the gap between the links 14 and 22, shorter than the
total length of the gap and thickness of the links 14 and 22.
Thus, according to the slide position of the pin 19b in the body
19c, the piston 19a can be set selectively, (1) in the position
which the piston 19a is inserted to the holes 13b and 22b, the each
end of the piston 19a does not protrude from the hole 13b, 22b (see
FIG. 4), or (2) in the position which the piston 19a is inserted to
the holes 14b and 22b, the end of the piston 19a does not protrude
from the hole 14b, 22b (see FIG. 6).
In other words, the piston 19a can be switched, (1) in the position
which the piston 19a is inserted in the holes 13b and 22b, and is
not inserted in the hole 14b (see FIG. 4), or (2) in the position
which the piston 19a is inserted in the holes 14b and 22b, and is
not inserted in the hole 13b (see FIG. 6). The piston 19a serve as
a member connecting selectively the holder 20 to either the link 13
or 14 without relative rotation for fixing the posture of the
links.
The piston 19a has the cut-circle sectional form fitting to the
holes 13b, 14b and 22b, if the piston 19a is inserted in the holes
13b, 14b and 22b, the piston 19a can not rotate around the holes
13b, 14b and 22b, so that the phase of the piston 19a is fixed to
the holes 13b, 14b and 22b in the rotate direction.
Thus, (1) if the piston 19a is inserted in the holes 13b and 22b,
the rotation angle .theta.1 of the link 22 to the link 13 is fixed,
(2) if the piston 19a is inserted in the holes 14b and 22b, the
rotation angle .theta.2 of the link 22 to the link 14 is fixed.
Furthermore, the controller 80 can control the slide position in
the rotation axis direction of the piston 19a.
Due to the above construction, the work conveying apparatus 1 can
selectively fixes the rotation angle .theta.1 of the link 22 to the
link 13 or the rotation angle .theta.2 of the link 22 to the link
14, when the arm 20 is driven in the vertical extending direction
and the window 5 is moved down, as shown in FIG. 2, if the
inclining posture of the holder 20 is turned to the posture
inclining leftward, the slide position of the piston 19a is
controlled to fix the rotation angle .theta.1, and when the window
5 is moved down, as shown in FIG. 3, if the inclining posture of
the holder 20 is turned to the posture inclining rightward, the
sleeve position of the piston 19a is controlled to fix the rotation
angle .theta.2.
Thus, in the work conveying apparatus 1, the rotation angle
.theta.1 of the links 13 and 22, or the rotation angle .theta.2 of
links 14, 22 can be selectively fixed, the inclining posture of the
holder 20 automatically turns in concert with the arm 10, so that
the means of driving may not be added which rotates the holder 20
(the window 5) to change the inclining posture.
Thus, the work conveying apparatus 1 may only include the driving
means for lifting the work without the driving means for rotating
it.
The driving means for rotating is dispensed, so that the weight
supported by the arm 10 is lightened, the driving means for lifting
the work (the motor disposed in the joint 15) can be downsized and
lightened.
The mechanism includes the shafts 18a and the piston 19a, which can
fix the posture of the holder against the link 13 or the link 14,
the shafts 18a connect the links 13, 14 and 22 to rotate each
other, the piston 19a selectively joints the link 13 or 14 to the
holder 20 without rotating each other, so that the holder 20 can be
easily and surely fixed the posture against the link 13 or 14.
In the alternative structure fixing the rotation angle .theta.1 and
.theta.2, the angle of the link 22 to the link 13 or 14 can be fine
tuned as following.
As shown in FIG. 7, the motor 61 is disposed in the lower joint 18.
The rotation angle of the link 22 to the link 13 or 14 can be fine
tuned by the motor 61.
In detail, the link 22 includes an inner link 22A and an outer link
22B, the link 22B is arranged in the outside of the link 22A, and
the link 22B supports the holder 20.
The link 22A and 22B can rotate to the rotation axis of the joint
relatively.
The link 22B has a pulley peripheral, and a driving belt 62 is
looped over the link 22B and the driving shaft of the motor 61
rotating the link 22B.
The holes 22a and 22b are formed in the link 22A connected to the
link 13 and 14.
The rotation angle .theta.1 and .theta.2 of the link 22A to the
link 13 and 14 are respectively fixed by the piston 19a.
The main body of the motor 61 is fixed in the side of the link
22A.
The other members including the links 13, 14 and the plunger 19 are
the same as the above described structure, so that they are not
described again.
Due to the above structure, for example as shown in FIG. 2, when
the rotation angle .theta.1 of the links 13 and 22 is fixed and the
window 5 is assemble to the rear window frame 7a, the arm 10 is
extended by the vertical length and the window 5 is moved down and
moved to the height of the rear window frame 7a. If the inclination
of the rear window 7a differs a little from that of window 5, the
link 22B is rotated to the link 22A by the motor 61, the
inclination of the window 5 is fine tuned and the inclination of
the window 5 can be adjusted to that of the rear window frame
7a.
The rotation angle .theta.1 of the inner link 22A to the link 13 is
fixed, but the link 22B is rotated to the link 22A by the motor 61,
the posture of the holder 20 (window 5) against the link 13 is fine
tuned.
Thus, the accuracy for tuning the posture of the window 5 and the
quality for assembling the window 5 to the rear window frame 7a can
be improved.
The work conveying apparatus 1 can be constructed as following.
As shown in FIG. 8, the work conveying apparatus 1 includes a
balancer-structure as following. A wire 73 is suspended between the
trolley 40 and the holder 20, supports the weight of the holder 20
and the window 5, so that the arm 10 is not effected the load
involving the weight during moving and that the load for the motor
is reduced which is set in the joint 15 of the arm 10.
One end of the wire 73 is connected to the body 41 of the trolley
40, the other end is connected to the holder 20.
A balancer cylinder 71 is set to the body 41. The cylinder 71
includes a cylinder body 71a, a piston 71b and a pulley 71c; the
piston 71b can move against the body 71a, the pulley 71c is set at
the end of the piston 71b. The piston 71b can move to the
substantially horizontal direction.
Another pulley 72 is also set to the body 41, the wire 73 is looped
over the pulley 71c and 72.
The piston 71b of the cylinder 71 is moved, then the length of the
wire 73 between the pulley 72 and the holder 20 is changed which is
looped over the pulley 71c and 72. Thus, the length of the wire 73
is changed in accordance with moving the window 5 by the arm 10, so
that the weight for the arm 10 is effectively reduced (canceled),
in spite of the movement of the arm 10 (the window 5 is moved up by
the arm 10 shortened by vertical length or the window 5 is moved
down by the arm 10 extended by vertical length).
In the balancer-structure, if the position of the cylinder 71 and
the pulley 72 in the direction to the assembly line L is fixed, as
shown in FIG. 8, depending on the position of the end of arm 10 (or
the holder 20) in the direction of the assembly line L, the looped
part of the wire 73 over the pulley 72 may be out of the connect
part of the holder 20 with respect to the position in the direction
of the assembly line L.
In other words, the wire 73 under the pulley 72 supports the holder
20 and the window 5 at an inclined angle .theta.a to the vertical
down.
In this position, the load F works on the wire 73 along the wire 73
which is connected to the holder 20, the wire 73 inclines at angle
.theta.a to the vertical direction, and the horizontal component of
the load [Fsin.theta.a] works on the joint which the wire 73
connected to the holder 20.
Thus, when the window 5 is set to the front window frame 7b, if the
horizontal component [Fsin.theta.a] works on the holder 20, the
operation force can not be reflected to the device 80 which the
operator controls the holder 20, therefore, the control of the arm
10 and the like can not be stabilized.
Then, the work conveying apparatus 1 is constructed that the
cylinder 71 is set to the body 41 moving along the direction of the
assembly line L, and that the horizontal component [Fsin.theta.a]
cannot work on the holder 20 in spite of the moving (posture) of
the arm 10.
The cylinder 71 and the pulley 72 is set to the body 41 through the
slide member including a guide rail 74 and the like, when the
horizontal force works on the wire 73 under the pulley 72, the
cylinder 71 and the pulley 72 move together to the direction
canceling the force.
Due to the above construction, as shown in FIG. 8, if the wire 73
is inclined to the vertical direction and the horizontal component
[Fsin.theta.a] works on the holder 20, as shown FIG. 9, the
cylinder 71 moves to the direction canceling the horizontal
component [Fsin.theta.a], so that the horizontal component
[Fsin.theta.a] cannot work on the holder 20.
Furthermore, in this case, the cylinder 71 moves to the position
where the wire 73 extends from the pulley 72 to the vertical
down.
Thus, in spite of the posture of the arm 10, the pulley 72 is set
over the joint which the wire is connected to the holder 20, so
that the wire 73 can be suspended vertically and the horizontal
force is prevented from working on the holder 20, therefore, the
holder 20 can be conveyed and controlled stably.
INDUSTRIAL APPLICABILITY
The present invention is applicable in the industrial instrument as
the work conveying apparatus, holding a work, conveying the work to
an assembled position, and changing the posture of the work applied
to the assembled position.
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